Lyophilization, or freeze-drying, is an advanced food preservation method. We start by keeping the fruit at icy temperatures, and freezing it, and then placing it in a vacuum. As the ambient pressure drops, the frozen water in the fruit sublimates (vaporizes) without melting, removing 98 percent of its water content. The cellular structure of freeze-dried fruits remains intact, and bacteria or fungi cannot develop since there is not enough moisture for them to thrive.
Using heat dehydration to produce dehydrated fruits is a more straightforward approach to removing water content. Warm air in an oven, dehydrator, or sun evaporates moisture from fruits. The purpose is to make them dry to prevent microbial growth and spoilage. Since the fruit experiences drying heat for a considerable period to dehydrate, this process can change its chemical makeup and structure.
Apart from the procedural difference, there are several other differences between dehydrated and freeze-dried fruits. Let us take a look at them below.
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Health Safety
Freeze-dried fruits: Freeze-dried fruits preserve their nutrients; low-temperature freeze-drying protects enzymes and vitamins that cannot withstand high temperatures. So freeze-dried fruit retains more nutrients than other methods, making them a healthier option. However, freezing and air exposure during rehydration may reduce the efficacy of several vitamins, especially vitamin C.
Dehydrated fruits: Dehydrated fruits may lose more nutrients than freeze-dried ones. Heat and prolonged dryness can break down vitamin C and other heat-sensitive vitamins. Because dried fruit has fiber, vitamins, and minerals, it is also generally wholesome.
Taste and smell
Freeze-dried fruits: These are popular because of their prominent taste – sublimation preserves their flavor. Rehydrating these fruits restores some flavor and texture, but not as much as fresh fruit. However, owing to its delicious taste, it is extensively used in preparing desserts, cereal meals, and cakes.
Dehydrated Fruits: Dehydrated fruits taste milder than freeze-dried fruits – heat can transform sugars into caramel when drying, changing the taste. The flavor is good, but the fruit becomes chewy – so overall, it does not taste as vibrant as freeze-dried fruits.
Texture
Freeze-dried fruits: Fruits, when freeze-dried, turn crisp and firm; moisture-loss without heat makes their texture light and airy. Water may make freeze-dried fruit taste like fresh fruit, but of course, it cannot be exactly that way. The crispness of freeze-dried fruits makes it an enjoyable snack that can also add a tasty crunch to dishes.
Dehydrated Fruits: Fruit remains chewy and thick after drying with heat. However, dehydrated fruit is still edible after rehydrating but does not take on its original form.
Shelf-life
Freeze-dried fruits: These last long – years in properly sealed containers. Since it has little water, microbes cannot grow in them and make them perish. Freeze-dried fruits are especially useful as emergency supplies and camping food owing to their prolonged freshness.
Dehydrated Fruits: They have a reasonably long shelf life but probably less than freeze-dried fruit. If stored properly in airtight cases, dried fruits can last longer.
Functions
Freeze-dried fruits: You can prepare many dishes using freeze-dried fruit. It is light and easy to rehydrate, so hiking and camping food supplies typically contain these. People add it to chocolates, cereals, and trail mixes.
Dehydrated Fruits: Many desserts, snacks, salads, yogurt, and cereals contain dehydrated fruits, as well as recipes that require a chewier fruit texture.
Final words
Freeze-dried fruits are becoming more and more popular nowadays, yet many of us tend to confuse them with dehydrated fruits. Reading this short article can help us clear our confusion and understand which one to buy based on our requirements and preferences.